Notch sensing control system for a partition assembly machine

ABSTRACT

A fluid flow sensing control system to sense the presence of notches in a series of longitudinal partition strips and initiate the insertion of a cross strip into the notches in a continuous process to produce a cell-type filler for a carton. A stream of fluid under pressure is directed across a gap in a fluid flow interruption sensing head from a series of emitting orifices to a corresponding series of collecting orifices. One of a plurality of longitudinal partition strips is directed to pass through the gap in the sensing head, thereby disrupting the normal flow from the emitting to the collecting orifices. The passage of a notch in the longitudinal partition is sensed and the signal is processed by a fluid logic system, which in turn causes a transverse partition strip to be inserted by a feeding mechanism into the aligned notches in the longitudinal strips. It should be understood that longitudinal strips are in parallel with the sensed strip so that the transverse strip is inserted in all longitudinal strips at the same time. Also these sets of plural longitudinal strips are introduced in series into the insertion area. Provision is also made to automatically clear the collecting orifices of any buildup of corrugated material debris blown off of the longitudinal strips.

United States Patent 1 Kozlowski et a1.

[ 1 Jan. 23, 1973 [54] NOTCH SENSING CONTROL SYSTEM FOR A PARTITION ASSEMBLY MACHINE [75] Inventors: Tadeusz Kozlowski, Toledo, Ohio,

Primary Examiner-Andrew R. .luhasz Assistant Examiner-Leon Gilden Att0rneyD. T. lnnis et al.

[57] ABSTRACT A fluid flow sensing control system to sense the presence of notches in a series of longitudinal partition strips and initiate the insertion of a cross strip into the notches in a continuous process to produce a celltype filler for a carton. A stream of fluid under pressure is directed across a gap in a fluid flow interruption sensing head from a series of emitting orifices to a corresponding series of collecting orifices. One of a plurality of longitudinal partition strips is directed to pass through the gap in the sensing head, thereby disrupting the normal flow from the emitting to the collecting orifices. The passage of a notch in the longitudinal partition is sensed and the signal is processed by a fluid logic system, which in turn causes a trans-- verse partition strip to be inserted by a feeding mechanism into the aligned notches in the longitudinal strips. It should be understood that longitudinal strips are in parallel with the sensed strip so that the transverse strip is inserted in all longitudinal strips at the same time. Also these sets of plural longitudinal strips are introduced in series into the insertion area. Provision is also made to automatically clear the collecting orifices of any buildup of corrugated material debris blown off of the longitudinal strips.

2 Claims, 8 Drawing Figures PATENTEDJAHZB I973 SHEET 1 OF 5 INVENTOR Evens? KozLowsw ERNEST HPEmBER w 76 15. flfl z FIG. I

ATTOQUQVS PRIOR ART PATENTEDmzs I973 3,712,183

SHEET 2 [IF 5 68 FIG 2 g PRIOR ART :5 4 INVENTOR. PRIOR ART PRIOR ART lAvEosz KozLowsm BY ERNEST H emsazmo (ATVs/Rum PATENTEDJAH 23 1975 SHEET 3 BF 5 FIG. 5

PATENTEDJAH 23 I973 SHEET a UF 5 PATENTEDJAN23 ma SHEET 5 OF 5 FIG. 8

INVENTOR. TADEUSZ KOZLOMJSKI EEMEQ'T HRzmsaaTom (ATORUEQRS NOTCII SENSING CONTROL SYSTEM FOR A PARTITION ASSEMBLY MACHINE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to machines for assembling longitudinal and transverse strips into a celltype filler for use in cartons. More specifically, this invention relates to the control circuit for the transverse strip feeder in such machines. Yet more specifically, this invention relates to an improved control circuit for such machines, which senses the presence of a notch in the longitudinal strips and actuates the transverse strip feeder in response to the passage of a notch. Most particularly, this invention relates to an improved control circuit for such machines which senses the presence of a notch in the longitudinal strips and utilizes a fluid logic system to cause the insertion of a transverse strip into the longitudinal strips.

2. Description of the Prior Art The basic concept of assembling cell-type fillers for cartons by inserting, one at a time, a series of transverse partitions in a moving plurality of longitudinal partition strips is well known in the art. For example, such a machine is shown in US. Pat. No. 2,754,731. The basic method used in the prior art of controlling the insertion of the transverse partitions is shown in FIGS. 12 and 13 of the above noted patent and in FIGS. [-4 of the drawings herein. The longitudinal strips are commonly aligned with a series of spacer bars mounted on a moving conveyor which presents the longitudinal partitions at the assembly point. The insertion is initiated by the spacer bar raising a series of adjustable trip levers, one at a time as the spacer bar passes, to open a control valve. This function has proven workable, but has presented a number of problems. The trip levers must be individually set for each change in size of the longitudinal partition strips, since the trip levers are positioned to coincide with the location of upwardly directed notches in the longitudinal strips. It should be clear that this setting, which is generally done by an eye-ball" alignment process on the part of the machine operator, can easily lead to errors in the timing of the insertion of the transverse strips, causing a defective cell to be produced. Also, there is frequently a relatively high friction factor between the spacer bar and the trip lever causing the conveyor to undergo a jerking motion leading to possible misalignment between the longitudinal and transverse partitions. The present invention overcomes all of these problems by sensing the presence of a longitudinal partition notch with a single sensor, which touches no moving parts of the machine, and utilizing a fluid logic system to sequence the feeding of transverse strips one at a time.

SUMMARY OF THE INVENTION This invention relates to apparatus for inserting the transverse partition strips into plural longitudinal strips in sequence, with the notched edge of one of the aligned longitudinal strips passing through a pneumatic sensing head of a fluid logic system and being sensed to trigger the operation of the transverse partition insertion phase of the operation of the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a partition assembly apparatus incorporating the control system of the prior art.

FIG. 2 is a schematic drawing of the control circuit of the prior art.

FIG. 3 is an elevation view showing the valve operating mechanism of the prior art in its normal position.

FIG. 4 is an elevation view showing the valve operating mechanism of the prior art in its operational position.

FIG. 5 is a perspective view of a partition assembly apparatus incorporating the improved control and sensing equipment of the present invention.

FIG. 6 is a perspective view of the sensing head and mounting of the present invention.

FIG. 7 is a sectional elevation view of the sensing head of the present invention.

FIG. 8 is a schematic drawing of the control circuit of the present invention.

DETAILED DESCRIPTION This invention relates to machines used to assemble longitudinal and transverse partition strips into a celltype filler for cartons. In such machines, a plurality of longitudinal strips are usually arranged across the width of a moving conveyor belt. These longitudinal strips have a series of upwardly opening notches spaced along the length of the strip. The corresponding notches of the plurality of longitudinal strips are aligned across the width of the moving conveyor carrying the strips. The moving conveyor serves to present the longitudinal strips to a single assembly station where a transverse partition is inserted in the aligned notches. This process is repeated as each set of notches reaches the assembly station until an entire cell is completed. In the present invention, a fluid flow interruption sensing head is positioned to force the passage of at least one of the iongitudinal strips through an opening in the head just prior to the assembly station. In the sensing head itself, three jets of high-pressure fluid issue from emitting orifices on one side of the gap through which the longitudinal strip must pass and are captured by collecting orifices on the opposite side. Back pressure sensing devices are connected to the outlet of the collecting orifices. So long as the jets of air pass across the gap freely, a control signal in the form of a low pressure fluid flow is fed from the back pressure sensing device to a fluid logic system. Under such conditions, there is no output from the fluid logic system.

Referring now to the drawings, FIG. 1 shows an assembly apparatus, indicated generally by the numeral 10, which includes an illustration of the control mechanism of the prior art. The apparatus 10 includes a frame 12, formed by a pair of vertical support columns 14 and a horizontal connecting cross beam 16. A conveyor 18, supported by a frame 19, is provided to pass between the columns 14 of the frame 12 in a left to right direction. A plurality of longitudinal paper guides 20 are positioned above the conveyor 18 and fastened to the frame 12 by a suitable suspension member 21. A plurality of longitudinal partitions 22 (only one of which is visible in FIG. 1) having slots or notches 24 formed therein, are advanced on the conveyor 18 through the guides with the notches 24 directed upwardly. A plurality of transverse partitions 26 having downwardly directed notches formed therein are mounted on an inclined table 28. The inclined table 28 is attached to the frame 12 by suitable means not shown. A transverse angle plate 30 is positioned to urge the stack of transverse partitions 26 toward the frame 12 under the action of a cable 32, which is connected at its other end to a counterweight (not shown).

A knocker bar mechanism, generally indicated by the numeral 34, includes a frame 36 which is slideably attached within channels on the columns 14 of the frame 12. The knocker bar mechanism 34 includes a flat plate or knocker bar 38 which is attached to a connecting beam 42. The beam 42 is attached to a connecting rod 44 which, in turn, is fixed to a piston (not shown) mounted within an air cylinder 46. The air cylinder 46 is generally supported by the frame portion 36 and the knocker bar 38 reciprocates relative to the frame 36 and the air cylinder 46. The knocker bar 38 is positioned to reciprocate up and down adjacent to the rear edge of the paper guides 20. The vertical position of the knocker 38 is adjustable by means of a threaded rod 35 and a wheel 37. The rotation of the wheel 37 and the threaded rod 35 causes a cylinder mounting plate 31 to move up or down on the mounting posts 33, thereby raising or lowering the knocker bar 38.

As well known to those versed in the art, the knocker bar 38 is reciprocated to insert transverse partitions 26 into the slots 24 of the advancing longitudinal partitions 22. In this prior art embodiment, the reciprocation of the knocker bar 38 is controlled by a trip lever mechanism generally designated as 48. The trip lever mechanism 48 comprises a horizontal flat plate support bracket 50 attached to the conveyor frame 19, vertically extending bearing plates 52 attached to the support bracket 50, a drive shaft 54 rotatably mounted in the bearing plates 52, a valve trip lever 56 which is fixed to the drive shaft 54 and rotates therewith, a lever bar 58 which is pivotally connected to the drive shaft 54 by projecting pivot arms 59, a series of trip levers 60 which may be slid along the length of the lever bar 58 to various positions and then locked in the position selected, and an operating valve 62 which serves to control the cycling of the air cylinder 46. The longitudinal partitions 22 are aligned with their trailing edges in contact with a flight bar 64 which is attached to the surface of and moves with the conveyor 18. In the assembly of any particular cell-type structure by this apparatus 12, the number of trip levers 60 will be equal to the number of longitudinal partition slots 24, and the position of the trip levers 60 along the lever bar 58 will be such as to place the trip levers 60 in transverse alignment with the longitudinal partition notches 24 as the longitudinal partitions 22 pass under the knocker bar 38. The operation of the trip lever mechanism is clearly shown in FIGS. 3 and 4. A roller 61 attached to the lower portion of each trip lever 60 normally rolls along the top of the conveyor 18. However, when the flight bar 64 approaches any trip lever 60, the roller 61 is forced up by the flight bar 64. This motion in turn pivots the lever bar 58 and pivot arm 59, in turn causing the drive shaft 54 to pivot which thereby pivots the valve trip lever 56. The pivoting motion of the valve trip lever 56 depresses a button 63 on the upper portion of the operating valve 62 thereby opening the operating valve 62 and allowing the knocker bar 38 to reciprocate and insert a transverse partition 26 into the notches 24 of the longitudinal partitions.

This operation is illustrated clearly in the schematic circuit diagram shown in FIG. 2. Air under pressure is supplied from a source 66 by means of suitable piping 68 to a conventional four-way air piloted spool valve 70. The valve 70 isof the type which requires control air to be admitted at one end or the other to shift the spool to thereby control and direct the flow of air exiting from it. One source of control air is from the operating valve 62. The operating valve 62 is itself a normally closed valve which is opened only by the depression of the button 63 by the valve trip lever 56. As a safety measure, the operating valve 62 may not receive air until an electrical solenoid valve 72 has been actuated by turning on the machine main electrical control circuit. As a further safety measure, a second electrically controlled solenoid valve 74 which is normally open, is provided to ensure that the knocker bar 38 will be retracted should electrical power to the machinery fail. Thus in the control circuit shown in FIG. 2, introductionof air to the left side of the four-way valve 70 through a pilot air line 71, moves the valve to the position shown and will cause air to be introduced to the cylinder 46 through the line 76 to cause retraction of the connecting rod 44 and consequently the knocker bar 38 to which the connecting rod 44 is attached. In operation, depression of the button 63 on the valve 62 will allow air to be introduced to the right side of the spool valve 70 through a pilot air line 69 thereby shifting the flow of air from a knocker bar up air line 76 to a knocker bar down air line 78, thereby driving the piston of the air cylinder 46 downward. As a result, the knocker bar 38 will reciprocate downward, feeding a transverse partition 26 into the notches 24 of the longitudinal partitions. At the bottom of its stroke, the knocker bar 38 will mechanically trip a reset valve 80 to the left as viewed in FIG. 2. The valve 80 is similar to the operating valve 62, and upon shifting will introduce air into the pilot air line 71 of the four-way valve 70, thereby shifting the spool within the four-way valve 70 and causing air to be directed into the air line 76 once again. This will then cause retraction of the knocker bar 38 to its initial position. This cycle is repeated as each lever 60 is engaged by the bar 64.

Turning now to FIG. 5, the assembly apparatus 10 is seen to be generally the same as that shown in FIG. 1 and operates in substantially. the same manner. Those structural elements that are identical have been given the same reference numerals and the control system of the invention with its sensing head will now be described in detail. The cumbersome and involved trip lever mechanism 48 of FIG. 1 has been removed and has been replaced by a fluid notch sensing head assembly 82. Note that the sensing head assembly 82 is mounted on an existing extension 84 of the slideable knocker bar frame 36. The sensing head assembly 82 is mounted such that one of the longitudinal partitions 22 must pass through the sensing head assembly 82 prior to the point at which the knocker bar 38 would insert a transverse partition 26 into the notches 24 of the longitudinal partitions 22.

FIGS. 6 and 7 clearly show the details of the sensing head assembly 82, details which are not visible in FIG. 5. Referring first to FIG. 6, an inverted U" shaped guide channel 86 is machined from the lower portion of the extension 84 of the knocker bar frame 36. The sensing head 88, which is substantially of an elongated, inverted U shape with a projecting boss 89, is slideably mounted on the guide channel 86. The longitudinal adjustment of the sensing head 88 along the guide channel 86 is controlled by an adjusting screw 90 which is in threaded engagement with a threaded hole 91 in the projecting boss 89. The adjusting screw 90 extends through a split clamping slot 92, located in the lower portion of a clamp block 94 which is in turn secured to the extension of the knocker bar frame 84 by two bolts 96. Clamping force is applied to the split clamping slot 92 by means of a clamp screw 98, thus preventing the sensing head 88 from moving from a selected position. Nine air lines 99, 100, 101, 102, 103, 104, 105, 106 and 107 are attached to the sensing head 88. Air enters thesensing head 88 through the upper three air lines 99, 100 and 101, leaves the sensing head 88 through the lowermost three air lines 105, 106 and 107, while the three intermediate air lines 102, 103 and 104 are used to introduce air into the sensing head for a cleaning function to be explained later. Referring now to FIG. 7, which is a cross-sectional, elevational view of the sensing head 88 of FIG. 6, air is seen to enter the sensing head 88 through an inlet air line such as 100, pass through the top portion of the sensing head, and exit through an emitting orifice 108 directed across the gap between the legs of the generally inverted U shaped sensing head 88. It should be understood that each of the inlet air lines 99, 100 and 101 have corresponding emitting orifices such as 108. On the other side of the gap, between the legs of the sensing head 88, is a collecting orifice 109 which communicates with an outlet air line such as 106. Of course, each of the outlet air lines 105, 106 and 107 have corresponding collecting orifices 109. It may thus be seen that, with no obstruction present between the legs of the sensing head 88, there will be a net flow of air from the three inlet lines 99, 100 and 101 to and out of the three outlet air lines 105, 106 and 107. Under conditions to be described later in conjunction with the control circuit of this device, the air flow into the inlet air lines 99, 100 and 101 is stopped and air is introduced into the three cleansing air lines 102, 103 and 104 to dislodge debris which may have collected in the collecting orifices 109.

Referring now to FIG. 8, which is a schematic representation of the control circuit of the present invention, the elements enclosed within the dotted lines correspond to the sensing head 88. The control circuit shown in FIG. 8 replaces the valves 62 and 72 shown in FIG. 2, as well as the entire trip lever mechanism 48 shown in FIG. 1. Otherwise, the circuit used is identical to that shown in FIG. 2 and the elements operate in the same manner as previously described with reference to FIG. 2. With specific reference to FIG. 8, an inlet manifold 112 receives compressed filtered dry air from a source not shown. The manifold feeds three branch air lines 113, 114 and 115. The branch 113 is directed through a high-pressure air regulator 116 which maintains a constant air pressure supply of from to 30 psig to a four-way,-pilot operated one-way, spool valve 118, which is normally biased to provide a source of high-pressure air via a branch pipeline 119 to the inlet lines 99, 100 and 101 in the sensing head 88. The inlet lines 99, 100 and 101 terminate in the previously mentioned emitting orifices 108 which are directed across the gap in the sensing head 88 toward the collecting orifices 109. If there is no obstruction between the emitting orifices 108 and the collecting orifices 109, the air flow will continue across the gap in the sensing head 88 and exit through the outlet lines 105, 106 and 107. As shown in FIG. 8, however, a longitudinal partition 22 is shown in position in the gap in the sensing head 88, with a notch 24 aligned with the inlet line 100, its emitting orifice 108 and the outlet line 106 with its collecting orifice 109. It will be noted that the longitudinal partition 22 is shown in cross-section in FIG. 8 revealing its most common configuration. Two outer plys of liner board 23 are bonded to an inner corrugated medium 25. The inlet lines 101 and 99 are blocked by the longitudinal partition 22. This condition leads to a specific logic configuration which will be discussed after the various components of the control system itself are considered. The outlet lines 105, 106 and 107 are fed into back pressure sensing devices 120, 121 and 122 manufactured by Johnson Service of Milwaukee, Wis. Returning now to the manifold 112, the branch line 114 leads the incoming air to a low-pressure air regulator 124 which provides a source of lowpressure air of from 1% to 3 psig to each of the three back pressure sensors 120, 121 and 122. This is achieved by splitting the branch line 114 into three independent segments after the air is reduced in pressure by the low-pressure air regulator 124. Each of the back pressure sensors 120, 121 and 122 has an output line 125, 126 and 127. The output lines 125 and 127 are connected directly to a fluidic NOR gate 130, model FLB-25l manufactured by Johnson Service, Milwaukee, Wis. The outlet line 126 is fed to a second fluidic NOR- gate 132 (identical to the NOR gate 130), and whose output forms a third input for the fluidic NOR gate 130. The NOR gates 130 and 132 are logic elements whose characteristics are such that an output is obtained only when all of the inputs to the NOR gate are zero. Thus the NOR gate 130 has three inputs whose value must be zero before it will produce an output, while the NOR gate 132 has but a single input whose value must be zero before an output will be obtained. In the case of fluid element NOR gates, an input of zero is equivalent to no air pressure on the inlet line to the fluid NOR gate. The output of both NOR gates 130 and 132 will be a pulse of air. The output air is supplied to the NOR gate 130 by an air line 131 which is connected to the branch line 114, while the NOR gate 132 is supplied by an air line 133, also connected to the branch line 114. The output of the NOR gate 130 branches into two segments, air lines 137 and 138. The air line 137 is connected to an indicator panel 134 (made up of multiple fluid indicators 135, model FDM- manufactured by Johnson Service, Milwaukee, Wis.,) and the air line 138 is connected to an interfacing valve 136, model I25LA, manufactured by Humphrey Products, Kalamazoo, Mich. The interfacing valve 136 in turn receives a high-pressure air input from the branch line connected to the inlet manifold 112. The interfacing valve 136 is normally biased such that it will give no output unless it receives a signal from the fluidic NOR gate 130 through the air line 138. Upon receipt of a signal from the fluidic NOR gate 130, the air from the branch line 115 is allowed to pass through the interfacing valve 136 and enter the four-way spool valve 70 through the pilot air line 69 causing the air cylinder 46 to reciprocate the knocker bar 38. It will be noted then, that an air line 139 is connected from the branch line 114 to the output air line 138 from the NOR gate 130. The air line 139 supplies a small flow of air, under the control of a needle valve 143, to the operating mechanism of the interfacing valve 136. This air flow keeps the valve 136 partially switched, thereby increasing its speed of operation when a signal is received from the NOR gate 130. it will be also noted that a branch line 140 is connected from the output of the interfacing valve 136 to the indicator panel 134. A fixed pressure dropping resistor 141 is inserted in the branch line 140 to reduce the pressure from the interfacing valve 136 to a level acceptable by the indicator panel 134. The indicator panel 134 comprises a series of fluid flow indicators which give a visual confirmation of the operation of various functions in the control sequence. As previously noted, the fluidic NOR gate 130 has its output connected to the indicator panel 134 as, and in addition, the fluidic NOR gate 132 has its output connected to the indicator panel 134 through an air line 142. The operation of the system is as follows:

With no obstruction between all of the emitting orifices 108 and the collecting orifices 109, air is flowing through the outlet lines 105, 106 and 107 into the back pressure sensing devices 120, 121 and 122. The effect of this flow is to require the air introduced into the back pressure sensing devices 120, 121 and 122 by the branching of the low-pressure line 114 to be emitted through the outlet lines 125, 126 and 127. Under these circumstances, the NOR gate 132 will have inputs equivalent to a logic one" from the output lines 125 and 127 and an input equal to a logic zero from the fluid NOR gate 132, since the input to the fluid NOR gate 132 is a logic one" from the output line 126. The following truth table indicates all of the possible variations of inputs to the NOR gate 130:

TRUTH TABLE INPUTS TO NOR GATE 130 Sensor 120 l 0 l 0 l 0 Sensor 121 0 0 l 1 0 0 1 Sensor 122 0 0 0 0 0 1 l OUTPUT FROM NOR GATE 130 0 )0 l O 0 0 0 0 no air output I air output Note that the input to the NOR gate 130 from the sensor 121 will always be the inverse of the value shown in the Table, due to the presence of the NOR gate 132 between the Sensor 121 and the NOR gate 130.

It is obvious that there is only one set of input signals which will give an output signal from the NOR gate 130, namely, the configuration shown in FIG. 8, in which the input lines 101 and 99 are blocked and the input line 100 is open to the collecting orifice 109 of the output line 106, due to the presence of a notch 24 therebetween. Under these conditions, the air entering the back pressure sensing devices and 122 from the branches of the low-pressure line 114 is allowed to exit through the sensing head output lines 105 and 107 because of the lack of a back pressure created in these lines. This then gives a logic signal of zero in the back pressure output lines 125 and 127 into the NOR gate 130. The input to the NOR gate 132 is a logic one because the flow from the output line 126 is still flowing due to the passage of air from the input line 100 and emitting orifice 108 to the collecting orifice 109 of the output line 106. This being the case, the output from the NOR gate 132 is a logic zero, thereby giving all of the inputs to the NOR gate a value of logic zero and causing an output from the NOR gate 130. This is the logic configuration previously discussed, under which circumstances the interfacing valve 136 will allow a signal to pass causing the insertion of a transverse partition 26 into the longitudinal partition notches 24.

The longitudinal partitions 22 which pass through the sensing head 88 frequently have small pieces of paper, resulting from the notching operation, attached to the notch 24. This debris may be blown off the notch 24 by the air stream from the emitting orifices 108 to the collecting orifices 109, the debris tending to accumulate and clog the collecting orifices 109. As a result, a false signal may be generated which will cycle the knocker bar 38. As an example, assume the collecting orifice 109, associated with the trailing outlet line 107, becomes blocked. As a result, back pressure sensor output line 127 will provide a constant logic zero signal to the NOR gate 130. Thus, as soon as the partition 22 has passed beyond the collecting orifices 109 associated with the outlet lines 107 and 106, a false signal to insert a transverse partition 26 will be generated.

This is because the logic zero signal from the output.

line 127 combined with the logic one signal from the output line 126 and the logic zero signal from the output line 125 (due to the fact that the partition 22 is still blocking the collecting orifice 109 of the sensing head outlet line 105) is equivalent to the logic state in which longitudinal partitions 22 are in position to have a transverse partition 26 inserted.

it has been found that the clogging of an orifice 109 takes place over a relatively long period of time. Thus, if the outlet lines 105,106 and 107 along with their associated collecting orifices 109 are blown clean between sets of longitudinal partitions 22, no clogging will occur. To achieve this function, a fluid counter 144 which will give an air pulse after a specific number of counts is utilized. ln this preferred embodiment, the counter used is a model SAC-24 manufactured by Humphrey Products, Kalamazoo, Mich. The operation of the counter 144 is as follows: The counter 144 is preset for the number of transverse partitions 26 to be placed in each cell unit to be assembled. As pointed out in FIG. 2, the downward stroke of the knocker bar 38 trips the valve 80, giving an output air pulse through the air line 71. A branch air line 145, from the air line 71, is used as an input to the counter 144. Each pulse of air released by the valve 80 is counted by the counter 144. When the pre-set number of counts has been reached, the counter 144 passes a pulse of air via air line 146 to the valve 118. The air for this purpose is furnished by a branch air line 147, connected to the counter 144, of the branch line 113. The pulse of air to the valve 1 18 shifts the flow of air from the air line 119, connected to the inlets 99, 100 and 101, to anair line 148 connected to the cleaning air lines 102, 103, and 104 and also resets the counter 144 to count the next set of air pulses.

With the foregoing in view, a general summary of the operation is as follows: When a notch passes through the sensing head, at one point the center orifice will be open to flow through the notch while the leading and trailing orifices will be blocked. In this case, the fluid logic system will give an output, causing a transverse partition to be fed and inserted into the aligned notches in the longitudinal partitions. The slight operating delay inherent in fluid logic systems is utilized in this case to allow the notch to clear the sensing head before the transverse partition is fed. Also provided is a system to automatically clean the collecting orifices of any corrugated dust between cycles. This control system has proven to be especially rugged, dependable and easily adjusted for cell size changes. In addition, the use of fluid logic has avoided the problems associated with using conventional electrical relay logic in the dusty environment surrounding such machines. Namely, relays are frequently subject to malfunctioning in dusty areas if elaborate precautions are not taken to prevent the infiltration of dust into the relay enclosures. Finally, as pointed out previously, the multiple problems of the conventional trip lever control system have been completely eliminated by the use of the improved control system of the present invention.

We claim:

1. The method of signalling the insertion of transverse partitions into longitudinal notched partitions, comprising, directing three separated horizontal flows of air across the path of movement of said longitudinal partitions at the level of the notches, sensing the interruption in the flow of said three air flows due to the passage of said longitudinal partitions, and signalling the insertion of a transverse partition when flow is blocked in two of said three flows and flow is present intermediate the two blocked flows.

2. The method of claim 1 further comprising the step of periodically reversing the direction of flow of all of said three air flows. 

2. The method of claim 1 further comprising the step of periodically reversing the direction of flow of all of said three air flows. 